How to merge two arrays in php

In PHP, merging two arrays can generally be achieved through the array_merge() function and array_unique() function.

The array_merge() function merges two or more arrays into one array and returns the merged array. If two arrays have the same key, the later value will overwrite the earlier value.

The array_unique() function can remove duplicate values ​​from the array and return the deduplicated array.

Let’s explain in detail how to use these two functions to merge two arrays.

Method 1: Use array_merge() function and array_unique() function

First, we need to define two arrays, for example:

$arr1 = array('a', 'b', 'c', 'd');
$arr2 = array('c', 'd', 'e', 'f');

Then, we can use array_merge( ) function merges two arrays into one array:

$arr = array_merge($arr1, $arr2);

At this time, the $arr array is:

array('a', 'b', 'c', 'd', 'c', 'd', 'e', 'f');

It can be seen that the $arr array contains repeated elements.

Next, we can use the array_unique() function to remove duplication and save the deduplicated array in a new array:

$arr = array_unique($arr);

At this time, the $arr array is:

array('a', 'b', 'c', 'd', 'e', 'f');

As you can see, there are no duplicate elements in the $arr array.

The complete code is as follows:

$arr1 = array('a', 'b', 'c', 'd');
$arr2 = array('c', 'd', 'e', 'f');
$arr = array_merge($arr1, $arr2);
$arr = array_unique($arr);
print_r($arr);

Method 2: Use the " " operator and array_unique() function

There is also a method to merge two arrays Operation, that is, use the " " operator and the array_unique() function.

We can also define two arrays:

$arr1 = array('a', 'b', 'c', 'd');
$arr2 = array('c', 'd', 'e', 'f');

Then, we can use the " " operator to combine the two arrays and assign them to a new array:

$arr = $arr1 + $arr2;

At this time, the $arr array is:

array('a', 'b', 'c', 'd', 'e', 'f');

You can see that the $arr array contains all elements, but there are duplicate elements.

Next, we can use the array_unique() function to remove duplication and save the deduplicated array in a new array:

$arr = array_unique($arr);

At this time, the $arr array is:

array('a', 'b', 'c', 'd', 'e', 'f');

As you can see, there are no duplicate elements in the $arr array.

The complete code is as follows:

$arr1 = array('a', 'b', 'c', 'd');
$arr2 = array('c', 'd', 'e', 'f');
$arr = $arr1 + $arr2;
$arr = array_unique($arr);
print_r($arr);

To sum up, we can use the array_merge() function and array_unique() function, or use the " " operator and array_unique() function to achieve the The operation of overlapping and merging two arrays.

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